Transmission fluid warming and cooling system

Abstract

A system for heating and cooling the transmission fluid including a heat exchanger adapted to transfer heat between an engine coolant and a transmission fluid and a controller for controlling a valve to place the system into a select one of three modes including a heater core priority mode wherein no engine coolant flows to the heat exchanger, a heating mode wherein hot engine coolant flows directly to the heat exchanger from the engine and a cooling mode wherein cool engine coolant flows directly to the heat exchanger from the radiator, whereby the transmission fluid is heated in an efficient manner with minimal impact on passenger compartment heating.

1. A vehicle comprising:
 a passenger compartment; 
 an internal combustion engine; and 
 an automatic transmission using transmission fluid and transmitting power from the engine to drive wheels to propel the vehicle, and a system for heating and cooling the transmission fluid, said system including:
 a heat exchanger fluidly connected to the engine and transmission, said heat exchanger being adapted to receive engine coolant from the engine, direct transmission fluid to the transmission and transfer heat between the engine coolant and the transmission fluid; 
 a passenger compartment heater core in fluid connection with both the engine and passenger compartment, said heater core being adapted to receive engine coolant from the engine, and to transfer heat between the engine coolant and air for the passenger compartment; 
 a radiator fluidly connected to the engine and the heat exchanger, said radiator being adapted to cool the engine coolant; 
 a first valve fluidly connected between the engine and the heat exchanger and being adapted to selectively allow or prevent the flow of engine coolant from the engine to the heat exchanger; 
 a second valve fluidly connected between the engine, the heat exchanger, and the radiator and being adapted to selectively allow fluid flow of engine coolant from the radiator to a select one of the engine and the heat exchanger; and 
 a controller for controlling the first and second valves to place the system into a select one of several modes including, a heating mode wherein hot engine coolant flows directly to the heat exchanger from the engine, and a cooling mode wherein cool engine coolant flows directly to the heat exchanger from the radiator and a heater core priority mode wherein no engine coolant flows to the heat exchanger, whereby transmission fluid temperature regulation occurs in an efficient manner with minimal impact on passenger compartment heating. 
 
 
     
     
       2. The vehicle of  claim 1  wherein the system further includes a thermostat connected between the engine and the radiator and being adapted to selectively allow fluid flow of engine coolant from the engine to the radiator; and the several heating modes further includes a heater core priority mode wherein when the thermostat is closed no engine coolant flows to the heat exchanger. 
     
     
       3. The vehicle of  claim 1  wherein the system further includes a second valve fluidly connected between the engine, the heat exchanger, and the radiator and being adapted to selectively allow fluid flow of engine coolant from the radiator to a select one of the engine and the first valve; the controller also controls the second valve; and the several heating modes further includes a heater core priority mode wherein no engine coolant flows to the heat exchanger. 
     
     
       4. The vehicle of  claim 1  wherein the radiator includes a high temperature section and a low temperature section and the second valve is connected to the low temperature section. 
     
     
       5. The vehicle of  claim 1  wherein the system further comprises a fluid channel between the radiator and the engine and a thermostat located in the channel. 
     
     
       6. The vehicle of  claim 1  wherein the system further comprises a heater core fluid return channel extending between the heater core and the engine and a hot coolant return channel leading from the heat exchanger to the heater core fluid return channel. 
     
     
       7. The vehicle of  claim 1  wherein the system further comprises a cool coolant supply channel extending between the radiator and the heat exchanger with the second valve being located in the cool coolant supply channel. 
     
     
       8. The vehicle of  claim 1  wherein the system further comprises a heater core fluid channel extending between the engine and the heater core and a hot coolant supply channel leading from the heater core fluid channel to the first valve. 
     
     
       9. The vehicle of  claim 8  wherein the system further comprises:
 a cool coolant supply channel extending between the radiator and the first valve with the second valve being located in the cool coolant supply channel; 
 a shunt channel extending between the first valve and the heat exchanger. 
 
     
     
       10. The vehicle of  claim 1  wherein the system further comprises a temperature sensor for sensing sump temperature, second and a temperature sensor for measuring engine coolant temperature. 
     
     
       11. The vehicle of  claim 1  wherein the system further comprises a first timer for determining when to switch the first and second valves triggered based on a rate of change of temperature of the engine coolant and having a time value based on a measured starting temperature and a second timer for determining when to switch the first and second valves triggered based on movement of a transmission control switch and having a time value based on a function of the starting temperature. 
     
     
       12. A system for heating and cooling a transmission fluid for use in a vehicle with a passenger compartment, an internal combustion engine, an automatic transmission using the transmission fluid and transmitting power from the engine to drive wheels to propel the vehicle, said system comprising:
 a heat exchanger fluidly connected to the engine and transmission, said heat exchanger being adapted to receive engine coolant from the engine, direct transmission fluid to the transmission and transfer heat between the engine coolant and the transmission fluid; 
 a passenger compartment heater core in fluid connection with both the engine and passenger compartment, said heater core being adapted to receive engine coolant from the engine, and to transfer heat between the engine coolant and air for the passenger compartment; 
 a radiator fluidly connected to the engine and the heat exchanger, said radiator being adapted to cool the engine coolant; 
 a first valve fluidly connected between the engine and the heat exchanger and being adapted to selectively allow or prevent the flow of engine coolant from the engine to the heat exchanger; 
 a second valve fluidly connected between the engine, the heat exchanger, and the radiator and being adapted to selectively allow fluid flow of engine coolant from the radiator to a select one of the engine and the heat exchanger; and 
 a controller for controlling the first and second valves to place the system into a select one of several modes including, a heating mode wherein hot engine coolant flows directly to the heat exchanger from the engine, a cooling mode wherein cool engine coolant flows directly to the heat exchanger from the radiator and a heater core priority mode wherein no engine coolant flows to the heat exchanger, whereby transmission fluid temperature regulation occurs in an efficient manner with minimal impact on passenger compartment heating. 
 
     
     
       13. The system of  claim 12  wherein the system further includes a thermostat connected between the engine and the radiator and being adapted to selectively allow fluid flow of engine coolant from the engine to the radiator; and the several heating modes further includes a heater core priority mode wherein when the thermostat is closed no engine coolant flows to the heat exchanger. 
     
     
       14. The system of  claim 12  wherein the system further includes a second valve fluidly connected between the engine, the heat exchanger, and the radiator and being adapted to selectively allow fluid flow of engine coolant from the radiator to a select one of the engine and the first valve; the controller also controls the second valve; and the several heating modes further includes a heater core priority mode wherein no engine coolant flows to the heat exchanger. 
     
     
       15. The system of  claim 12  wherein the system further comprises a heater core fluid return channel extending between the heater core and the engine and a hot coolant return channel leading from the heat exchanger to the heater core fluid return channel. 
     
     
       16. The system of  claim 12  wherein the system further comprises a cool coolant supply channel extending between the radiator and the heat exchanger with the second valve being located in the cool coolant supply channel. 
     
     
       17. The system of  claim 12  wherein the system further comprises a heater core fluid channel extending between the engine and the heater core and a hot coolant supply channel leading from the heater core fluid channel to the first valve. 
     
     
       18. The system of  claim 17  wherein the system further comprises a cool coolant supply channel extending between the radiator and the first valve with the second valve being located in the cool coolant supply channel, a shunt channel extending between the first valve and the heat exchanger. 
     
     
       19. The system of  claim 12  wherein the system further comprises a temperature sensor for sensing sump temperature, a temperature sensor for measuring engine coolant temperature. 
     
     
       20. The system of  claim 12  wherein the system further comprises a first timer for determining when to switch the first and second valves triggered based on a rate of change of temperature of the engine coolant and having a time value based on a measured starting temperature and a second timer for determining when to switch the first and second valves triggered based on movement of a transmission control switch and having a time value based on a function of the starting temperature. 
     
     
       21. A system comprising:
 a first valve fluidly connected between an engine and a heat exchanger for transferring heat between engine coolant and transmission fluid; 
 a second fluid valve connected between the engine, the heat exchanger and a radiator and being adapted to selectively allow fluid flow of the engine coolant from the radiator to a select one of the engine and the heat exchanger; and 
 a controller for controlling the first and second valves to place the system into a select one of several modes including: a heating mode wherein hot engine coolant flows directly to the heat exchanger from the engine, a cooling mode wherein cool engine coolant flows directly to the heat exchanger from the radiator, and a heater core priority mode wherein no engine coolant flows through the heat exchanger. 
 
     
     
       22. The system of  claim 21  further comprising a cool coolant supply channel extending between the radiator and the heat exchanger, with the second valve being located in the cool coolant supply channel. 
     
     
       23. The system of  claim 21  further comprising:
 a heater core fluid channel extending between the engine and the heater core; and 
 a hot coolant supply channel leading from the heater core fluid channel to the first valve. 
 
     
     
       24. The system of  claim 23  further comprising a cool coolant supply channel extending between the radiator and the first valve, with the second valve being located in the cool coolant supply channel, a shunt channel extending between the first valve and the heat exchanger. 
     
     
       25. The system of  claim 21  further comprising:
 a first temperature sensor for sensing sump temperature; and 
 a second temperature sensor for measuring engine coolant temperature, each of the first and second temperature sensor being linked to the controller.